1. Field of the Invention
This invention relates to a gear assembly and, more specifically, to a planocentric hypocycloidal gear assembly designed to receive an input horsepower of between one-third and five horsepower.
2. Related Art
Planocentric hypocycloidal gear assemblies are used for speed reduction and have typically been utilized in association with large machinery. These gear assemblies generally comprise an input shaft cover plate, an eccentric input shaft, an input shaft bearing placed on the eccentric input shaft and within a hole in the input shaft cover plate, a first pinion having drive holes and a first bearing hole, a first pinion bearing fitted inside the first pinion bearing hole, a second pinion having drive holes and a second bearing hole, a second pinion bearing fitted inside the second pinion bearing hole, an eccentric input shaft bearing, drive pins, secured to an output shaft plate which itself is secured to an output shaft, an output shaft bearing disposed on the output shaft, an output shaft cover plate, and a housing surrounding the entire assembly. The drive pins are equipped with sleeves to alternately adjust the total diameter presented to the drive holes. Specifically, the sleeve is placed over portions contacting the drive holes and the first and second pinions. However, the sleeve does not extend into the drive hole in the output shaft cover plate.
In operation, the eccentric input shaft is coupled to a driving motor. The driving motor drives or rotates the eccentric input shaft. As the eccentric input shaft rotates, the eccentricity of the shaft drives the first and second pinions in a camming action. The rotation of the shaft and pinions is assisted by the various bearings. As the pinions are driven in a planocentric hypocycloidal path as defined by the eccentricity of the eccentric input shaft, the sleeves of the drive pins extending through the drive holes of the pinions are in turn driven which rotates output cover plate and output shaft. It is specifically noted that the drive pins do not come into direct contact with the pinion surface, that being reserved for the drive pin sleeves.
Due to the construction of these planocentric hypocycloidal gear assemblies, the number of parts required has discouraged the application of this technology to small machinery. While small scale models without the drive pin sleeves of these larger planocentric hypocycloidal gear assemblies have been utilized for demonstrations purposes, namely, to demonstrate the planocentric hypocycloidal path, these models can not be seriously considered "working" models in any capacity. Moreover, the small demonstration models will not support an input application of between one-third and five horsepower. Accordingly, there has been no attempt to modify these larger planocentric hypocycloidal gear assemblies for small machinery involving an input application of between one-third and five horsepower.
As a result, there is a need in the art to modify the planocentric hypocycloidal gear assembly and to reduce the number of parts and associated costs in order to adapt this technology for lower input horsepower applications.